Before figuring out how to choose the auxiliary gas, it is necessary to understand why the auxiliary gas is used and what it does. After experience summary: the use of auxiliary gases in addition to blowing away the slag in the coaxial cutting seam, but also can cool the surface of the processed object, reduce the heat-affected zone, cooling the focusing lens, to prevent soot from entering the lens seat to pollute the lens and cause the lens to overheat; in addition, some cutting gases can also play a role in protecting the base material. The choice of gas pressure and type of gas has a greater impact on the cutting process, the choice of auxiliary gas type will have a certain impact on the performance of cutting, including cutting speed, cutting thickness, etc..
High-speed fiber laser cutting machine can use the auxiliary gases are mainly air, nitrogen, oxygen and argon, the following we are for different auxiliary gases, to introduce their uses and characteristics.
1, air: air can be provided directly by the air compressor, so the price is very cheap compared to other gases. Although air contains about 20% oxygen, but the cutting efficiency is far less than oxygen, and the cutting ability is similar to nitrogen. Trace amounts of oxide film will appear on the cutting surface, but can be used as a measure to prevent the coating layer from peeling off. Yellowing of the cut end.
The main applicable materials are aluminum, aluminum alloy, stainless copper, brass, electroplated steel, non-metal, etc. However, when cutting products with high quality requirements, aluminum, aluminum alloy, stainless steel, etc. are not suitable for air, because air will oxidize the base material.
2, nitrogen: some metals in the cutting time using oxygen will form an oxide film on the cutting surface, the use of nitrogen can be carried out to prevent the appearance of oxide film oxidation-free cutting. Thus, there can be directly fused, coated, corrosion resistance and other characteristics. The cut end face is white. The main applicable plates are stainless steel, electroplated steel, brass, aluminum, aluminum alloy, etc.
3, oxygen: mainly used for laser cutting carbon steel. The use of oxygen reaction heat large surface to improve cutting efficiency at the same time, the resulting oxide film will improve the absorption factor of the beam spectrum of reflective materials. The end face of the cut black or dark yellow. Mainly applicable to calendered steel, dissolving structure with calendered steel, mechanical structure with carbon steel, high tension version, tool plate, stainless steel, electroplated steel, copper, copper alloy, etc.
4, argon: argon is an inert gas, used in laser cutting machine cutting to prevent oxidation and nitriding, also used in welding, compared with other processing gases, the price is high, the corresponding increase in cost. The end face of the cut is white. The main applicable materials are titanium, titanium alloy, etc.
In the above, many gases can be used in general, the focus should be considered cutting costs and the requirements of the product, such as cutting stainless steel materials, when the quality or surface quality of the product does not do very high requirements, such as cutting products later need to go through painting and other process processing procedures, you can use air as the cutting gas, can reduce a lot of costs. When the cut product is the product, there is no subsequent process, it is necessary to use protective gas, such as craft products, etc. Therefore, the gas must be selected according to the characteristics of the product in the cutting down process.